The Causal Effect of Mortgage Refinancing on Interest-Rate Volatility: Empirical Evidence and Theoretical Implications

Abstract

This paper investigates the effects of mortgage-backed securities (MBS) hedging activity on interest-rate volatility and proposes a model that takes these effects into account. An empirical examination suggests that the inclusion of information about MBS considerably improves model performance in pricing interest-rate options and in forecasting future interest-rate volatility. The empirical results are consistent with the hypothesis that MBS hedging affects both the interest-rate volatility implied by options and the actual interest-rate volatility. The results also indicate that the inclusion of information about the MBS universe may result in models that better describe the price of fixed-income securities.